JPH0529312B2 - - Google Patents

Description

(e) the tube body 4, the end walls 6, 8 and the capillary tube 14;
16 is made of alkali lime silicate glass or alumino lime silicate glass, (f) the end walls 6, 8 are the tube body 4, and the capillary tubes 14, 1
6.He- which is hermetically connected to the pump connecting pipe piece and cathode connecting pin by glass solder.
In the Ne gas discharge tube, (g) the end walls 6, 8 are formed as cylindrical disks inserted into the tube body 4, and (h) the end wall 6 is limited by the end of the cylindrical cathode 37.
(i) The glass solder 17, 19 completely covers the outer surface of the end wall on one end wall and the inner surface of the other end wall. He−Ne
gas discharge tube.

[Detailed description of the invention]

Industrial Application Field The present invention provides: (a) a cylindrical tube body having a cylindrical cathode present inside and an end wall inserted into the end of the tube body and provided with a cylindrical hole; (b) an end a capillary tube made of glass inserted into a cylindrical hole in the wall and sealed in the end wall; (c) a pump connection piece hermetically secured to one of the end walls; (d) passing through a hole parallel to the axis. (e) the tube body, the end wall and the capillary tube are made of alkali-lime-silicate glass or alumino-lime-silicate glass; (f) ) The present invention relates to a He--Ne gas discharge tube whose end wall is hermetically connected to the tube body, capillary tube, pump connection tube piece and cathode connection pin by means of glass solder.

BACKGROUND OF THE INVENTION He--Ne gas discharge tubes are used in particular for measuring equipment. In known gas discharge tubes, the individual parts are interconnected by welding. This production is generally carried out automatically. Hard glasses are used which have a low coefficient of expansion and are suitable for automatic manufacture. These gas discharge tubes have the disadvantage that the hard glass used has only limited tightness against helium. Gas discharge tubes therefore have only a limited lifespan. In gas discharge tubes of this type, it is known to seal and fix the Brewster window by means of a glass solder ring surrounding it (see German Patent Application No. 3103385-2326561). European Patent Publication No. 119408, Federal Republic of Germany Utility Model Registration No. 7203534).

In many applications, such as in spaceflight and in laser gyros,
A significantly longer service life is required.

OBJECT OF THE INVENTION The object of the invention is to provide a gas discharge tube of the type mentioned at the outset, which has significantly lower helium losses than known gas discharge tubes.
The objective was to provide a He-Ne gas discharge tube.

Means for Solving the Problem The object is achieved according to the invention in a He-Ne gas discharge tube of the type mentioned at the outset, (g) the end wall is formed as a cylindrical disk inserted into the tube body, and (h ) the end of the cylindrical cathode is configured as a stop for a limiting end wall, and (i) the glass solder is applied entirely to the outer surface of the end wall on one end wall and on the inner surface thereof on the other end wall; This problem can be solved by covering the problem.

EXAMPLES Next, the present invention will be explained in detail with reference to illustrated examples.

The gas discharge tube 2 shown in the drawing has a cylindrical tube body 4
has. At the end of this tube, disc-shaped end walls 6, 8 are provided.
has been inserted. The end walls 6 and 8 are provided with a central hole into which the capillary tubes 14, 16 are inserted, which are arranged at their inner ends at a predetermined distance from each other in the conventional manner. ing.

The dimensions of the bore and of the outer circumference of the end walls 6 and 8 should be selected in such a way that there is as little as possible, but sufficient play between the end wall and the tube body and the capillary tube, which play is then This is necessary in order to allow stress-free alignment of the capillary tubes during mounting, taking into account the intersection. End wall 6
and 8 has a stepped portion 18 on its outer periphery and a stepped portion 20 on its inner periphery. These steps, together with the inner tube wall or outer periphery of the capillary tube, respectively form a solder joint for receiving a glass solder which serves to sealingly fix the capillary tube to the end wall and the end wall to the tube body.

In the illustrated embodiment, the steps 18, 20 of the two discs 6 and 8 respectively point outwardly in opposite directions.
The steps may also be arranged oriented in the same direction, ie facing into the tube interior on one side. These can also be omitted as described below.

The tube body 4 and the end walls 6, 8 are made of alkali-lime-silicate glass or alumino-lime-silicate glass. Alkali-lime silicate glass, which belongs to soft glasses, has the following main components: CaO (5-12% by weight), alkali (13-20% by weight), _SiO2 (remaining). Alumino-lime silicate glass, which belongs to medium-hard glass, has the following characteristic contents: Al ₂ O ₃ (3.5-10% by weight); CaO
(6-12% by weight); Alkali (8-23% by weight),
_SiO2 (remainder). Less than 3% by weight of other components can also be present (“Werkstoffkunde der Hoch-
vakuumtechik” Volume 2, page 2; VEB
Deutscher Verlag der Wissen-schaften,
(See Berin 1962).

For example, mainly SiO ₂ about 72%, Na ₂ O + K ₂ O14
%, CaO 9%, MgO 3 -4% and Al ₂ O ₃ 1% alkaline lime silicate glass of conventional float glass quality can be used. Such glasses have a density of 2.5 g/cm ³ and a coefficient of linear thermal expansion of 8.5-9.5·10 ⁻⁶ /K. These glasses can be used for tubes, end walls and capillary tubes. A very useful alumino-lime-silicate glass, commercially available from Fa. Schott Ruhrglas of Germany under the trade name "AR-Glasklar", has approximately the following chemical composition (% by weight):
_SiO269 , _B2O31 , _Al2O34 , _{Na2O13 , K2O3 ,}
BaO2, CaO5 and MgO3; Linear expansion coefficient α _20/300
is 9.0·10 ⁻⁶ /K; the transition temperature is 520° C. and the density is 2.52 g/cm ³ . Alkali-lime-silicate glass and alumino-lime-silicate glass have high helium airtightness, which is about ¹⁰ times greater than the hard glass from which He-Ne gas discharge tubes are generally made, so glass sealing from hard glass is possible. A significantly longer service life is expected than the known gas discharge tubes manufactured by the company.

As solder material it is advantageous to use crystalline glass solder. Fa.Schott Glas−werke
The crystalline glass solder “Glas No. 8597” has been found to be particularly advantageous. This glass solder
It melts at 435℃ and can be reheated to 450℃ after soldering without deteriorating its strength.
However, it is also possible to use stable glass solders, especially of the lead borosilicate type.

The glass solder can be applied in the form of separately presintered solder rings (1-2 mm wide and 2 mm thick). However, as shown in FIG. 2, it is also possible to use solder discs with a corresponding thickness.

At its outer end, the capillary tube has sections 22, 24 with a diameter larger than the capillary diameter. In the space created in this way,
Anode pins 26 and 28 protrude into both capillary tubes 14 and 16, respectively. At the outer end, the capillary tube is sloped at a Brewster angle α and a Brewster window 30 is fixed to this slope with glass solder. For this purpose, it is advantageous to use thin glass solder disks, so that a planar soldering between the ramp and the Brewster window takes place.

In FIG. 1, a hole 32 is provided in the right-hand end wall 6, into which a pump connection piece 34, which is also secured with glass solder 36 and sealed, is fitted. Fixing and sealing of the anode pins 26 and 28 is likewise accomplished by glass solder.

The tube is furthermore provided in a known manner with a cathode 37 in the form of an aluminum cylinder pushed into the tube 4 and fixed on a connecting pin 39 guided through one of the end walls, in this case the end wall 8. has been done. This cylindrical cathode 37 and its connecting pin 39 are
In FIG. 1 it is indicated by a dotted line. The connecting pin 39 is likewise soldered to the end wall 8.

Manufacturing can be carried out as follows. That is, first the Brewster window is soldered to the capillary tube and the anode pins 26 and 28 are soldered. The end walls 6 and 8 are then fitted into the tube 4 with solder rings or discs. In this case, the end face of the cylindrical cathode can be used as a stop. A capillary tube is further fitted onto the end wall and held in alignment. If the solder joints are aligned, the parts are then soldered in one step as described above.

In the case of the gas discharge tube shown in exploded view in FIG. 2, the individual components substantially correspond to those shown in FIG. The individual components of this embodiment are shown in assembled condition in FIG. Regarding the parts corresponding to those shown in the embodiment of FIG. 1, reference is made to the above description of FIG. The difference in this case is that both end walls 6 and 8 consist of simple disks without steps. For soldering, solder disks 17 and 19 are provided, which disks have an outer diameter and a hole 1.
As for the diameter of 3 or 21, it is equal to that of the end wall. Furthermore, the end wall and the associated solder disk have identical holes 15 for the pump connection piece 34 on the one hand and holes 23 for the cathode connection pin 39 on the other hand. End walls 6 and 8 and associated solder discs 1
7 and 19 can be manufactured by ultrasonic machining from a glass plate or a sintered glass solder disk using the same tool, respectively. In this case it is advantageous to omit a step in the end wall.

The gas discharge tube is soldered with a vertical axis. In this case, as shown in FIG.
is designed to lie substantially in the same plane as the upper edge of the tube 4.

The lower end of the cylindrical cathode 37 is connected to the solder disk 1
9 and the solder disk also rests on the end wall 8
The end wall also lies in the same plane as the lower end of the tube 4. In this case, a support disk 41 is provided for holding, on which the tube 4 and the end wall 8 rest.

For alignment of the capillary tube, the third
It is advantageous to use a device as shown in the figure. In this case, a clamping bracket 42 is fastened to a clamping base 40 having a base plate 43, which bracket is provided at its front end with mutually colinear wedge-shaped grooves 44, in which the said type The preassembled tube 2 is fitted with its capillary tubes 14 and 16 at their outwardly projecting ends. The capillary tube is then mechanically tightened into the groove 44 using a tightening member (not shown). In the embodiment shown in FIG. 3, the clamping base 40 is secured by screws 45 to an L-shaped support member 46 with a seat 48. In the embodiment shown in FIG. In this way, an alignment of the two capillary tubes with respect to their axis and with respect to the position of the Brewster window is possible, which is of great importance for the operation and efficiency of the gas discharge tube. The mating play between the end wall and tube body 4 and the capillary tubes 14 and 16 should be selected to allow stress-free alignment.

Next, the gas discharge tube attached to the device as described above is connected to the solder disk 17 so that the solder joints and holes 15 and 2 on the inner and outer peripheries of the end walls are connected.
3, the device is inserted into the furnace in an upright position, with the action of gravity and capillary action achieving complete "wetting" of the bonding surfaces. Solder bonding should be performed at a heating or cooling rate of about 7°C/min.

Of course, a capillary tube prepared in the above manner may be attached to the anode pin and the cathode 37 as the case may be.
It is also possible to first solder the end wall together with the connecting pin 39 separately to the end wall and then to solder the end wall thus produced to the tube body 4. When using the glass solder "7597" mentioned above, the same glass solder can be used for continuous soldering. Otherwise, it is necessary to use glass solders with sufficiently different soldering temperatures.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a He-Ne gas discharge tube according to the invention, and FIG. 2 is an advantageous one of the He-Ne gas discharge tube.
An exploded perspective view of the embodiment and FIG. 3 is a side view of the apparatus for manufacturing the discharge tube of FIG. 2. 4... Cylindrical tube body, 6, 8... End wall, 10, 1
2... Hole, 13, 15, 21, 23... Hole, 1
4, 16... Capillary tube, 17, 19... Solder disk, 18, 20... Step portion, 22, 24... Hole division, 23... Hole, 26, 28... Anode connection pin, 30... Brewster's window, 34...Pump connecting tube piece, 37...Cylindrical cathode, 39...Connecting pin, α...Brewster angle.

[Claims]

1. A method for manufacturing a laser cathode, comprising:
A substantially hemispherical basic element 1 made of glass or glass-ceramic material is provided with an aluminum or aluminum alloy coating (Al coating) on its inside by a vacuum coating process, and the purified basic element 1 is transferred to a vacuum unit. the conductive base 2 having an ^opening 9 aligned with the inside of the cathode base element 1 to be coated in a container of The pressure of the remaining gas is 2×10 ^-7
the vessel is filled with at least one laser gas under slight pressure, while the Al coating is applied essentially simultaneously in a coating process which is controllable with respect to the rate of layer growth. with a step, the Al coating also covering a partial area of the base 2, thus creating a conductive connection between the coated basic element 1 and the base 2, without interrupting the vacuum state, the Al coating The base element 1 thus prepared is brought into position in the container on the gas inlet device 7 through which the mixture of laser gases is injected for a few millimeters.